On the same day the United States announced the arrest of a 19-year old attempting to leave the country to join ISIS , a top State Department official said the American efforts to combat ISIS ' powerful online message are working .

The anti-ISIS messaging campaign is keeping disaffected youth from joining the extremist group , Under Secretary of State for Public Diplomacy and Public Affairs Richard Stengel told CNN 's Elise Labott on Monday .

`` We have evidence that there are young people who are not joining because we have somehow interceded , '' Stengel said . `` They 're reading the messages , they 're hearing the messages -- not just from us but from the hundreds of Islamic clerics who have said that this is a perversion of Islam , from the hundreds of Islamic scholars who have said the same thing . ''

`` It 's a very small cohort , '' Stengel said of the so-called `` foreign fighter '' cases originating from the United States .

As part of his role at the State Department , Stengel overseas the Center for Strategic Counterterrorism Communications , which aims to counter propaganda from ISIS .

ISIS has been effective over the past several months at bringing its message to young people around the world through a series of highly produced and graphically violent videos , and through online forums .

`` We 're out there contesting that space , '' said Stengel , `` and I think we 're doing well there . ''

Why is ISIS so successful at luring Westerners ?

Stengel recently returned from a trip to the Middle East , during which he met with officials from U.S. regional coalition partners in the fight against ISIS .

During his interview with CNN , Stengel weighed in on controversy surrounding comments made last week by Vice President Joe Biden , which seemed to call into question the commitment of some of those same key partners .

Stengel said the uproar over Biden 's remarks , which he later apologized for , is a `` peripheral issue . ''

`` I do n't think that deters anybody at all , '' Stengel added , `` and in fact I think they regard it as a very minor distraction compared to this real challenge of mobilizing all of our collective forces against this abhorrent organization . ''

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Anti-ISIS messaging campaign is working , State Department official says

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`` Young people who are not joining because we have somehow interceded , '' he says

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19-year-old American accused of wanting to join ISIS is arrested Monday